Question

Consider two 1 Liter containers of two metal salts, X and M, connected by a salt bridge. The electrodes in the containers are of minimal volume and made of graphite, which doesn’t participate in the reactions.

Container one contains is 0.95 molar in M+, 0.05 molar in M2+.

The equation for standard reduction of this is M2+ + e- → M+. All species stay in solution. Its standard potential is 0.05V vs SHE.

Container two contains 0.05 molar X+, 0.95M X2+.

The equation for standard reduction of this is X2+ + e- → X+. All species stay in solution. Its standard potential is 0.83V vs SHE.

a. What is the standard potential of this cell(hint- difference between the electrodes’ standard potentials)?

b. What are the potentials at each electrode?
c. As this cell gets discharged X2+ gets reduced to X+, and M+ gets oxidized to M2+.

Graph the potential of the cell, and each electrode, as a function of concentration, as the cell is discharged. DO A GOOD GRAPH. I HATE POORLY DONE GRAPHS

For example, as it gets discharged, more of the starting materials get oxidized and reduced. Say graph the points each 0.1 or 0.01M as the concentrations change, and what gets you a smooth looking graph.

How much energy is released as the cell goes from its initial state to its final state? ​

Answer 1

The standard or normal potential is the potential difference between the cell potential and the SHE.

Then the potential at each electrode is:

And the standard potential of the cell is:

The reaction quotient is:

Using the Nernst equation:

So, with the initial concentrations you given:

We know that: